Any hymenopterous insect of the family Ichneumonidæ
, of which several thousand species are known, belonging to numerous genera. [1913 Webster
" The female deposits her eggs upon, or in, the bodies of other insects, such as caterpillars, plant lice, etc. The larva lives upon the internal tissues of the insect in which it is parasitic, and finally kills it. Hence, many of the species are beneficial to agriculture by destroying noxious insects."